/*
 * Copyright (c) 2007-2011 by The Broad Institute of MIT and Harvard.All Rights Reserved.
 *
 * This software is licensed under the terms of the GNU Lesser General Public License (LGPL),
 * Version 2.1 which is available at http://www.opensource.org/licenses/lgpl-2.1.php.
 *
 * THE SOFTWARE IS PROVIDED "AS IS." THE BROAD AND MIT MAKE NO REPRESENTATIONS OR
 * WARRANTIES OF ANY KIND CONCERNING THE SOFTWARE, EXPRESS OR IMPLIED, INCLUDING,
 * WITHOUT LIMITATION, WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
 * PURPOSE, NONINFRINGEMENT, OR THE ABSENCE OF LATENT OR OTHER DEFECTS, WHETHER
 * OR NOT DISCOVERABLE.  IN NO EVENT SHALL THE BROAD OR MIT, OR THEIR RESPECTIVE
 * TRUSTEES, DIRECTORS, OFFICERS, EMPLOYEES, AND AFFILIATES BE LIABLE FOR ANY DAMAGES
 * OF ANY KIND, INCLUDING, WITHOUT LIMITATION, INCIDENTAL OR CONSEQUENTIAL DAMAGES,
 * ECONOMIC DAMAGES OR INJURY TO PROPERTY AND LOST PROFITS, REGARDLESS OF WHETHER
 * THE BROAD OR MIT SHALL BE ADVISED, SHALL HAVE OTHER REASON TO KNOW, OR IN FACT
 * SHALL KNOW OF THE POSSIBILITY OF THE FOREGOING.
 */

package org.broad.tribble.source;

import org.broad.tribble.Feature;
import org.broad.tribble.FeatureCodec;
import org.broad.tribble.readers.AsciiLineReader;
import org.broad.tribble.util.Positional;

import java.io.File;
import java.io.IOException;

/**
 * Iterator which records the position in the file at each step.
 * Useful for indexing.
 * User: jacob
 * Date: 2012/01/26
 */
public class PositionalIterator<T extends Feature> extends FeatureIterator<T> implements Positional {

    private long cachedPosition;

    public PositionalIterator(String inputFile, FeatureCodec codec, AsciiLineReader reader) throws IOException {
        super(inputFile, codec, reader);
    }

    protected void readNextRecord() throws IOException {
        this.cachedPosition = ((AsciiLineReader) this.reader).getPosition();
        super.readNextRecord();
    }

    public long getPosition() {
        return (hasNext()) ? cachedPosition : ((AsciiLineReader) this.reader).getPosition();
    }
}
